Here is the full list of all 31 The Dark Eye: Memoria achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Do You Like Riddles?
Try to tear down the wall with the golem.
Complete Chapter One.
Does Bryda know who you really are?
Turn the pig on the grill.
Find out who of the adventuring party lies at the first try.
Do you have the guts to start an argument?
Shards crack loudly.
Give Bryda the wrong astral accumulator.
Catch the rabbit at the first try.
Complete Chapter Two.
Find the fox within the labyrinth.
The forest is my home.
Defeat the spider.
Complete Chapter Three.
Ashes to ashes, stone to dust.
Stone, dust, stone, dust.
Complete Chapter Four.
Throw all items into the chasm.
Give all items to Xerxes.
Persuade the spirit of air to help you straight away.
Adjust the horns towards the spheres.
Collect all elementals.
Find the Caverns of Fail.
Complete Chapter Five.
Complete Chapter Six.
Complete Chapter Seven.
Make your decision.
Complete Chapter Eight.